Occupant Classification System
(OCS)
Introduction The Occupant Classification System (OCS)
categorizes the person in the front-passenger
seat. Depending on that result, the front-
passenger front air bag is either enabled or
deactivated.
The system does not deactivate:
R the side impact air bag
R the pelvis air bag
R the window curtain air bag
R the Emergency Tensioning Devices
Prerequisites To be classified correctly, the front passenger
must sit:
R with the seat belt fastened correctly
R in an almost upright position with their
back against the seat backrest
R with their feet resting on the floor, if possi-
ble
If the front passenger does not observe these
conditions, OCS may produce a false classi-
fication, e.g. because the front passenger:
R transfers their weight by supporting them-
selves on a vehicle armrest
R sits in such a way that their weight is raised
from the seat cushion
If it is absolutely necessary to install a child
restraint system on the front-passenger seat,
be sure to observe the correct positioning of
the child restraint system. Never place
objects under or behind the child restraint
system, e.g. cushions. The entire base of the
child restraint system must always rest on the seat cushion of the front-passenger seat. The
backrest of the forwards-facing child restraint
system must, as far as possible, be resting on the backrest of the front-passenger seat.
The child restraint system must not touch the
roof or be put under strain by the head
restraint. Adjust the angle of the seat back- rest and the head restraint position accord-
ingly.
Only then can OCS be guaranteed to function correctly. Always observe the child restraint
system manufacturer's installation instruc-
tions.
Occupant Classification System opera-
tion (OCS) The PASSENGER AIR BAG OFF indicator lamp
shows you whether the front-passenger front air bag is disabled.
X Turn the SmartKey to position 1or 2in the
ignition lock, or press the Start/Stop but-
ton once or twice on vehicles with KEY-
LESS-GO.
The system carries out self-diagnostics.
The PASSENGER AIR BAG OFF indicator lamp
must light up for approximately six seconds.
The PASSENGER AIR BAG OFF indicator lamp then displays the status of the front-
passenger front air bag. If the status of the
front-passenger front air bag changes while
the vehicle is in motion, an air bag display
message may appear in the instrument clus-
ter (Y page 260). When the front-passenger
seat is occupied, always pay attention to the
PASSENGER AIR BAG OFF indicator lamp. Be aware of the status of the front-passenger
front air bag both before and during the jour- ney. 52
Occupant safetySafety
If the PASSENGER AIR BAG OFF indicator
lamp:
R is lit : the front-passenger front air bag is
deactivated. It will then not be deployed in the event of an accident.
R does not light up : the front-passenger
front air bag is enabled. If, in the event of an accident, all deployment criteria are met,
the front-passenger front air bag is
deployed. G
WARNING
If the PASSENGER AIR BAG OFF indicator
lamp is lit, the front-passenger front air bag is disabled. It will not be deployed in the event of
an accident and cannot perform its intended
protective function. A person in the front-
passenger seat could then, for example, come
into contact with the vehicle's interior, espe-
cially if the person is sitting too close to the
dashboard. This poses an increased risk of
injury or even fatal injury.
When the front-passenger seat is occupied,
always ensure that:
R the classification of the person in the front-
passenger seat is correct and the front-
passenger front air bag is enabled or disa-
bled in accordance with the person in the
front-passenger seat
R the front-passenger seat has been moved
back as far back as possible.
R the person is seated correctly.
Make sure, both before and during the jour-
ney, that the status of the front-passenger
front air bag is correct. G
WARNING
If you secure a child in a child restraint system on the front-passenger seat and the
PASSENGER AIR BAG OFF indicator lamp is
off, the front-passenger front air bag can
deploy in the event of an accident. The child
could be struck by the air bag. This poses an
increased risk of injury or even fatal injury. Make sure that the front-passenger front air
bag has been disabled. The PASSENGER AIR
BAG OFF indicator lamp must be lit.
G
WARNING
If you secure a child in a forward-facing child
restraint system on the front-passenger seat
and you position the front-passenger seat too close to the dashboard, the child could, in the
event of an accident:
R come into contact with the vehicle's inte-
rior if the PASSENGER AIR BAG OFF indi-
cator lamp is lit, for example
R be struck by the air bag if the PASSENGER
AIR BAG OFF indicator lamp is off
This poses an increased risk of injury or even
fatal injury.
Move the front-passenger seat as far back as possible. Always make sure that the shoulder
belt strap is correctly routed from the vehicle
belt sash guide to the shoulder belt guide on
the child restraint system. The shoulder belt
strap must be routed forwards and down-
wards from the vehicle belt sash guide. If nec- essary, adjust the vehicle belt sash guide and
the front-passenger seat accordingly. Always
observe the child restraint system manufac-
turer's installation instructions.
If OCS determines that: R the front-passenger seat is unoccupied, the
PASSENGER AIR BAG OFF indicator lamp
lights up after the system self-test and
remains lit. This indicates that the front-
passenger front air bag is deactivated.
R the front-passenger seat is occupied by a
child of up to 12 month sold in a standard
child restraint system, the PASSENGER AIR BAG OFF indicator lamp lights up after the
system self-test and remains lit. This indi-
cates that the front-passenger front air bag
is deactivated.
But in the case of a 12-month-old child in a
standard child restraint system, the
PASSENGER AIR BAG OFF indicator lamp
can go out after the system self-test. This Occupant safety
53Safety Z
When the front-passenger seat is occupied,
always ensure that:
R the classification of the person in the front-
passenger seat is correct and the front-
passenger front air bag is enabled or disa-
bled in accordance with the person in the
front-passenger seat
R the person is seated properly with a cor-
rectly fastened seatbelt
R the front-passenger seat has been moved
back as far back as possible
If the PASSENGER AIR BAG OFF indicator
lamp remains lit when it should not, the front-
passenger seat may not be used. Do not
install a child restraint system on the front-
passenger seat. Have the Occupant Classifi-
cation System (OCS) checked and repaired
immediately at a qualified specialist work-
shop. G
WARNING
Objects between the seat surface and the
child restraint system could affect OCS oper- ation. This could result in the front-passengerair bag not functioning as intended during an
accident. This poses an increased risk of
injury or even fatal injury.
Do not place any objects between the seat
surface and the child restraint system. The
entire base of the child restraint system must
always rest on the seat cushion of the front-
passenger seat. The backrest of the forwards- facing child restraint system must, as far as
possible, be resting on the backrest of the
front-passenger seat. Always comply with the child restraint system manufacturer's instal-
lation instructions.
After the system self-test, the PASSENGER
AIR BAG OFF indicator lamp displays the sta-
tus of the front-passenger front air bag
(Y page 52).
For more information about the OCS, see
"Problems with the Occupant Classification
System" (Y page 56). Occupant safety
55Safety Z
Problems with the Occupant Classification System (OCS)
Be sure to observe the notes on "System self-test" (Y
page 54).Problem
Possible causes/consequences and
0050
0050Solutions The PASSENGER AIR
BAG OFF indicator
lamp lights up and
remains lit, even
though the front-
passenger seat is occu-
pied by an adult or a
person of a stature cor-
responding to that of an
adult. The classification of the person on the front-passenger seat is
incorrect.
X Make sure the conditions for a correct classification of the per-
son on the front-passenger seat are met (Y page 52).
X If the PASSENGER AIR BAG OFF indicator lamp remains lit, the
front-passenger seat may not be used.
X Have OCS checked as soon as possible at an authorized
Mercedes-Benz Center. The PASSENGER AIR
BAG OFF indicator
lamp does not light up
and/or does not stay
on.
The front-passenger
seat is:
R unoccupied
R occupied by the
weight of a child up
to 12 months old in a
child restraint sys-
tem OCS is malfunctioning.
X Make sure there is nothing between the seat cushion and the
child seat.
X Make sure that the entire base of the child restraint system rests
on the seat cushion of the front-passenger seat. The backrest of
the forward-facing child restraint system must lie as flat as pos- sible against the backrest of the front-passenger seat. If nec-
essary, adjust the position of the front-passenger seat.
X When installing the child restraint system, make sure that the
seat belt is tight. Do not pull the seat belt tight using the front-
passenger seat adjustment. This could result in the seat belt and the child restraint system being pulled too tightly.
X Check for correct installation of the child restraint system.
Make sure that the head restraint does not apply a load to the
child restraint system. If necessary, adjust the head restraint
accordingly.
X Make sure that no objects are applying additional weight onto
the seat.
X If the PASSENGER AIR BAG OFF indicator lamp remains off, do
not install a child restraint system on the front-passenger seat.
It is recommended that you install the restraint system on a
suitable rear seat.
X Have OCS checked as soon as possible at an authorized
Mercedes-Benz Center. 56
Occupant safetySafety
Deployment of Emergency Tensioning
Devices and air bags
Important safety notes G
WARNING
The air bag parts are hot after an air bag has
been deployed. There is a risk of injury.
Do not touch the air bag parts. Have a
deployed air bag replaced at a qualified spe-
cialist workshop as soon as possible. G
WARNING
A deployed air bag no longer offers any pro-
tection and cannot provide the intended pro-
tection in an accident. There is an increased
risk of injury.
Have the vehicle towed to a qualified special- ist workshop in order to have a deployed air
bag replaced.
It is important for your safety and that of your
passenger to have deployed air bags replaced and to have any malfunctioning air bags
repaired. This will help to make sure the air
bags continue to perform their protective
function for the vehicle occupants in the
event of a crash. G
WARNING
Pyrotechnic Emergency Tensioning Devices
that have been deployed are no longer opera- tional and are unable to perform their inten-
ded protective function. This poses an
increased risk of injury or even fatal injury.
Therefore, have pyrotechnic Emergency Ten-
sioning Devices which have been triggered
immediately replaced at a qualified specialist workshop.
An electric motor is used by PRE-SAFE ®
to
trigger the tightening of the seat belt in haz-
ardous situations. This procedure is reversi-
ble.
If Emergency Tensioning Devices or air bags
are deployed, you will hear a bang, and a small amount of powder may also be released. The
0075 restraint system warning lamp lights up. Only in rare cases will the bang affect your
hearing. The powder that is released gener-
ally does not constitute a health hazard, but it may cause short-term breathing difficulties in
people with asthma or other respiratory prob-
lems. To avoid this, you may wish to get out of
the vehicle or open the windows as soon as it is safe to do so.
Air bags and pyrotechnic Emergency Tension-
ing Devices (ETDs) contain perchlorate mate-
rial, which may require special handling and
regard for the environment. National guide-
lines must be observed during disposal. In
California, see www.dtsc.ca.gov/
HazardousWaste/Perchlorate/
index.cfm .
Method of operation During the first stage of a collision, the
restraint system control unit evaluates impor-
tant physical data relating to vehicle deceler-
ation or acceleration, such as:
R duration
R direction
R intensity
Based on the evaluation of this data, the
restraint system control unit deploys the
Emergency Tensioning Devices during a fron- tal or rear collision.
An Emergency Tensioning Device can only be
deployed, if:
R the ignition is switched on
R the components of the restraint system are
operational; see "Restraint system warning lamp" (Y page 43)
R the belt tongue is engaged in the buckle on
the respective front-passenger seat
The Emergency Tensioning Devices in the
rear compartment are deployed independ-
ently of the lock status of the seat belts. Occupant safety
57Safety Z
If the restraint system control unit detects a
more severe accident, further components of the restraint system are activated independ-
ently of each other in certain frontal collision
situations:
R Front air bags and driver's knee bag
R Window curtain air bag, if the system deter-
mines that deployment can offer additional protection to that provided by the seat belt
The front-passenger front air bag is activated
or deactivated depending on the person on
the front-passenger seat. The front-
passenger front air bag can only deploy in an accident if the PASSENGER AIR BAG OFF indi- cator lamp is off. Observe the information onthe PASSENGER AIR BAG OFF indicator lamp (Y page 43).
Your vehicle has two-stage front air bags.
During the first deployment stage, the front
air bag is filled with propellant gas to reduce
the risk of injuries. The front air bag is fully
deployed with the maximum amount of pro-
pellant gas if a second deployment threshold
is reached within a few milliseconds.
The deployment threshold of the Emergency
Tensioning Devices and the air bag are deter-
mined by evaluating the rate of vehicle decel-
eration or acceleration which occurs at vari-
ous points in the vehicle. This process is pre- emptive in nature. Deployment should take
place in good time at the start of the collision.
The rate of vehicle deceleration or accelera-
tion and the direction of the force are essen-
tially determined by:
R the distribution of forces during the colli-
sion
R the collision angle
R the deformation characteristics of the vehi-
cle
R the characteristics of the object with which
the vehicle has collided
Factors which can only be seen and measured
after a collision has occurred do not play a
decisive role in the deployment of an air bag, nor do they provide an indication of air bag
deployment.
The vehicle can be deformed considerably,
without an air bag being deployed. This is the
case if only parts which are relatively easily
deformed are affected and the rate of decel-
eration is not high. Conversely, air bags may
be deployed even though the vehicle suffers
only minor deformation. This is the case if, for
example, very rigid vehicle parts such as lon- gitudinal body members are hit, and sufficient
deceleration occurs as a result.
If the restraint system control unit detects a
side impact or that the vehicle is rolling over, the relevant restraint system components areactivated independently of one another
depending on the apparent type of accident.
If the system determines a need for additional
protection for the vehicle occupants, the
Emergency Tensioning Devices are deployed.
R Side impact air bags and pelvis air bag on
the side of impact, independently of the
Emergency Tensioning Device and the use
of the seat belt on the driver's seat and
outer seats in the second row
- the OCS system detects that the front-
passenger seat is occupied or
- the belt tongue is engaged in the belt
buckle of the front-passenger seat
R Window curtain air bag on the side of
impact, independently of the use of the
seat belt and independently of whether the
front-passenger seat is occupied
R Window curtain air bags on the driver's and
front-passenger side in certain situations
when the vehicle rolls over, if the system
determines that deployment can offer addi-
tional protection to that provided by the
seat belt
i Not all air bags are deployed in an acci-
dent. The different air bag systems work
independently of each other. 58
Occupant safetySafety
restraints, have this work carried out at a
qualified specialist workshop.
NECK-PRO luxury head restraints Example: Sedan
Do not insert your finger between the cushion
of the head restraint and the cover. Pay par-
ticular attention while resetting the NECK-
PRO luxury head restraints.
X Remove resetting tool 0043from the vehicle
document wallet.
X Slide resetting tool 0043into guide 0044
between the NECK-PRO luxury head
restraint and the rear cover of the head
restraint.
X Push resetting tool 0043downwards until you
hear the head restraint deployment mech-
anism engage.
X Pull out resetting tool 0043.
X With your hand flat, firmly push the NECK-
PRO luxury head restraint cushion back-
wards in the direction of arrow 0087until it
engages.
X Repeat this procedure for the second
NECK-PRO luxury head restraint.
X Put resetting tool 0043back into the vehicle
document wallet.
i If you have difficulty resetting the NECK-
PRO luxury head restraints, have this work carried out at a qualified specialist work-
shop. PRE-SAFE
®
(anticipatory occupant
protection system)
Introduction In certain hazardous situations, PRE-SAFE
®
takes pre-emptive measures to protect the
vehicle occupants.
Important safety notes !
Make sure that there are no objects in the
footwell or behind the seats. There is a dan- ger that the seats and/or objects could be
damaged when PRE-SAFE ®
is activated.
Although your vehicle is equipped with PRE-
SAFE ®
, the possibility of injury in the event of
an accident cannot be ruled out. Always
adapt your driving style to suit the prevailing
road and weather conditions and maintain a
safe distance from the vehicle in front. Drive
carefully.
Function PRE-SAFE
®
intervenes:
R in emergency braking situations, e.g. when
BAS is activated
R in critical driving situations, e.g. when phys-
ical limits are exceeded and the vehicle
understeers or oversteers severely
R on vehicles with the Driving Assistance
package: if BAS PLUS intervenes power-
fully or the radar sensor system detects an
imminent danger of collision in certain sit-
uations
PRE-SAFE ®
takes the following measures
depending on the hazardous situation detec-
ted:
R the front seat belts are pre-tensioned.
R the front-passenger seat is adjusted if it is
in an unfavorable position.
R if the vehicle skids, the sliding sunroof and
the side windows are closed so that only a small gap remains. The panorama roof with 60
Occupant safetySafety
power tilt/sliding panel is completely
closed.
R the air pressure in the side bolsters of the
seat backrests of the front active multicon-
tour seats is raised.
If the hazardous situation passes without
resulting in an accident, PRE-SAFE ®
slackens
the belt pre-tensioning. On vehicles with
active multicontour seats, the air pressure in
the side bolsters is reduced again. All settings
made by PRE-SAFE ®
can then be reversed.
If the seat belt pre-tensioning is not reduced:
X Move the seat backrest or seat back
slightly when the vehicle is stationary.
The seat belt pre-tensioning is reduced and
the locking mechanism is released.
The seat-belt adjustment is an integral part of
the PRE-SAFE ®
convenience function. Infor-
mation about the convenience function can
be found under "Belt adjustment"
(Y page 47). PRE-SAFE
®
PLUS (anticipatory occu-
pant protection system PLUS)
Introduction PRE-SAFE
®
PLUS is only available in vehicles
with the Driving Assistance package.
Using the radar sensor system, PRE-SAFE ®
PLUS is able to detect that a head-on or rear-
end collision is imminent. In certain hazard-
ous situations, PRE-SAFE ®
PLUS takes pre-
emptive measures to protect the vehicle
occupants.
Important safety notes The intervention of PRE-SAFE
®
PLUS cannot
prevent an imminent collision.
The driver is not warned about the interven-
tion of PRE-SAFE ®
PLUS.
PRE-SAFE ®
PLUS does not intervene if the
vehicle is backing up. PRE-SAFE
®
PLUS does not perform braking
actions while the vehicle is in motion or when Parking Guidance is active.
Function PRE-SAFE
®
PLUS intervenes in certain situa-
tions if the radar sensor system detects an
imminent head-on or rear-end collision.
PRE-SAFE ®
PLUS takes the following meas-
ures depending on the hazardous situation
detected:
R if the radar sensor system detects that a
head-on collision is imminent, the seat
belts are pre-tensioned.
R if the radar sensor system detects that a
rear-end collision is imminent:
- the brake pressure is increased if the
driver applies the brakes when the vehi-
cle is stationary.
- the seat belts are pre-tensioned.
The PRE-SAFE ®
PLUS braking application is
canceled:
R if the accelerator pedal is depressed when
a gear is engaged
R if the risk of a collision passes or is no lon-
ger detected
R if DISTRONIC PLUS indicates an intention
to pull away
If the hazardous situation passes without
resulting in an accident, the original settings
are restored. Automatic measures after an acci-
dent
Immediately after an accident, the following
measures are implemented, depending on
the type and severity of the impact:
R the hazard warning lamps are activated
R the emergency lighting is activated
R the vehicle doors are unlocked
R the front side windows are lowered Occupant safety
61Safety Z